Hopper for stokers and the like



' May 7, 1940.

R. E. YOUNG HOPPER FOR STOKERS AND THE Filed July 31, 1937 LIKE 3 Sheets-Sheet 1 Inveni' r':

,Yourg,

' Ra mond May 7, 1940. R. E. YOUNG HOPPER FOR STOKERS AND THE LIKE.

Filed Jul y 31, 1 93'! 3 Sheets-Sheet 2 Invehfor "Rqgmcn EYoun b5 W 2 May 7, 1940. R; E, Y NG 2,199,770

HOPPER FOR STOKERS AND THE LIKE Filed July 31, 1937 3 Sheets-Sheet 3 ITwT/entor' Patented May 7, 1940 PATENT OFFICE HOPPER FOR STOKERS AND THE LIKE Raymond E. Young, Harvey, Ill., assignor to Whiting Corporation, Harvey, 111., a corporation of Illinois Application my 31, 1937, Serial N5. 156,658 3 Claims. (01. 198-64) In many types of stokers for feeding solid fuel to furnaces there are provided hoppers from which the fuel is drawn by a suitable conveyor of the screw type, or the plunger type, and

5 thence delivered to the retort or fire pot for combustion. Domestic stokersare usually so built. The screw or other type conveyor is placed in communication with the lower portion of the hopper, and as the fuel is withdrawn by such conveyor the fuel must feed down through the hopper to the position of such conveyor. The action of the conveyor, especially when it is of the screw type, is frequently such as to produce boiling of the fuel in the hopper (that is--an l5 agitation of the fuel in the hopper, generally in the form of an upward movement in the forward portion of the hopper, a backward movement of.

the fuel 'in the upper portion of the hopper, and

a downward movement in the rearportion of the hopper), segregation of the fuel in the hopper (that istendency of the finer material to feed in the screw, leaving the larger material to collect in the hopper), and degradation of the fuel in the hopper (that is-breaking up of the larger pieces and with creation of an excess amount of fines). In addition to the above, the hopper should be so formed as to ensure proper and natural movement of the fuel downward to the conveyor, taking account of the natural tendency of the fuel to bridge" .or hold up in the hopper instead of descending properly to the conveyor position. e

In the past, there have-been provided various forms of agitators to assist the downward move-. ment of the fuel to the conveyor and to prevent such bridging or hanging. Any such devices are objectionable-because of the added expense of .construction, the use of power needed to operate them, the complications entailed by them in the 40 form of added parts subject to breakage and wear, and the noise of operation which they often produce. further degradation and segregation of the fuel in the hopper.

According to one feature of my invention, 1 so mount the hopper that it can be turned or rotated about an axis extending in a generally vertical direction. Thus, the hopper can be turned around such axis in order to carry the body of fuel around with the hopper. This will present said body of fuel to. the conveyor at different angles from time to time, and will present different portions of the body of fuel to the conveyor so that intime all portions of the bottom 56 face of the fuel body will have been presented Besides, such agitators tend to cause tothe conveyor, and fuel withdrawn from all said portions. Furthermore, by this arrangement, theconveyor is able to take fuel from the entire circular lower portion of the hopper uniformly, notwithstanding the fact that the con- 5 veyor, itself, is generally relatively narrow, and extends diametrically across the hopper bottom. Furthermore, with such arrangement it is not necessary to provide any downwardly and in- .wardly sloping floor for the hopper, as in the 0 past, to direct the fuel to the position of the conveyor, with consequent loss of fuel capacity for a hopper of given over all dimensions.

As another feature of my invention, I provide a driving relation between the conveyor and the 15 rotary hopper so that as the conveyor travels (for example, as the feed screw rotates) the hopper is simultaneously slowly rotated, thereby maintaining the desired harmony between conveyor and hopper movements. Such harmony is 20 maintained regardless of the speed of conveyor movement and also regardless of Whether the movement is continuous or intermittent.

More specifically, I form the hopper of generally spherical shape with a suitable delivery opening in its lowercentral portion for delivery of the fuel to the conveyor, and with a suitable (generally central) charging opening in its upper portion. The bottom delivery opening cuts off a circular segment from the bottom of the hopper, 30 and the angle of the tangent to the sphere at the position of the edge of such opening may be such as to ensure proper natural feed .of the fuel down to the hopper opening and to the conveyor substantially without clinging or hanging of the 35 fuel to the hopper sides. As a result, it is possible to use substantially the entire spherical portion of the hopper for fuel capacity, and eliminate the need of special false plates or guide plates for ensuring proper downward movement of" the 40 fuel along the hopper wall to the delivery open-'- The hopper, when ofspherical form presents a novel and attractive appearance of' distinctive form, but such "distinctive and novel appearance of the spherical species of the hopper construction is the subject of another application *for I design Letters Patent of the United States filedby me on the 19th day of July, 1937, as Serial No. D-70,527, which became Design Patent, No.

v 106,700, issued October 26, 1937.

Other objects and .uses of the invention will appear from .a detailed description of the same,

which consists in the features of construction,

and combinations of parts hereinafter described and claimed.

In the drawings:

Figure 1 shows a plan view of one embodiment of my invention, using a spherical hopper located off center with respect to the base housing or skirt;

Figure 2 shows a side elevation showing the construction of Figure 1;

Figure 3 shows a vertical longitudinal section on the line 3-3 of Figure 1 looking in the direction of the arrows;

Figure 4 shows a horizontal section on the line 5- 3 of Figures 2 and 3 looking in the direction of the arrows but on an enlarged scale; and

Figure 5 shows a cross section on the line 55 of Figures 1, 2, 3 and 4 looking in the direction of the arrows.

Referring first to Figures 1 and 2, the stoker construction therein shown includes the firepot Hi to which the fuel is fed by a screw conveyor ll in the well-understood manner. The conveyor reaches beneath a fuel hopper [2 wherein the body of coal or other fuel is contained. In the particular construction shown in Figures 1 to 5 inclusive, this hopper I2 is of generally spherical form and it will be noted that the vertical axis approximately intersects the axis of the feed screw.

The feed screw itself is accommodated in the throat member l3, and this throat connects with the open top trough section It beneath the position of the hopper. The upper edge of such trough section is defined generally by the plane IS. The spherical hopper of Figures 1 to 5 inclusive is cut off segmentally at the plane l5, as by removing a spherical segment from the sphere, said spherical segment being generally less in amount than one-half of the sphere. In the construction shown in the figures in question this spherical segment is formed by the trace of a line extending through the center of the sphere at an angle of substantially fifty-five degrees (55) to the vertical or thirty-five degrees (35) to the horizontal. sphere at the line of intersection with the plane I5, is substantially fifty-five degrees (55) from the horizontal plane, as shown by the dotted line 16 in Figure 3. The above angles and proportions are given merely by way of illustration and not by way of any limitation, except as I may limit the claims to follow.

Extending out from the sides of the top of the trough section I 4 are the horizontal segments I1 and I8, the edges of said segments coinciding generally with the line of intersection of the sphere with the plane l5. These side plates serve to close the lower side portions of the hopper, leaving the diametrical portion of the hopper at the position of the plane IS in coincidence with the open top, of the trough l4 so that fuel can descend from the hopper directly into the trough.

There is a series of sweeps or arms l9 secured to the inside of the hopper just above the plates l1 and I8 and reaching inwardly, so that as the hopper is rotated any fuel sustained by the plates I1 and I 8 will be moved towards the open top of the trough and delivered to the screw conveyor therein. These sweeps or arms l9 may be radial, as shown by the full lines,in Figure 4.

Extending up from the trough l4 and from the plates l1 and I8 there isthe circular flange 20 which forms a channel or trackway to receive the lower circular edge of the hopper and guide same as the hopper is rotated, keeping the hop- Likewise, the tangent to the per properly centered at all times. The lower edge of the hopper also carries the outwardly extending ring gear 2|, preferably of bevel type,

so that same can be conveniently driven by the bevel pinion 22 on the stub shaft 23. When said stub shaft is oifset as shown in Figure 4 the ring gear and pinion may be of hypoid type to ensure proper meshing. The stub shaft 23 may be driven in any convenient manner, as by proper connection with the driving mechanism contained within the housing 24, which housing contains the proper driving mechanism for the feed screw H also, and may be of any suitable form. A suitable motor such as the electric motor 25 is provided for driving all of the devices in selected manner.

Generally a 'fan 26 is provided for supplying air to the firepot through medium of a duct 21. In such case said fan may also be driven by the same electric motor 25. With such an arrangement it is customary to carry the duct along past the trough and feed screw throat, so placing the fan that the air coming off the impeller flows directly into the duct. It will be noted that, due to the inward turning of the lower edge portion of the hopper there is established suflicient space to pass the duct past the trough l4 and beneath the over-hanging side portion of the hopper.

In order to enclose and protect the driving and other devices I have provided a skirt or housing 28 for the same. The same is of generally fiat top form with a downwardly extending flange reaching substantially to the floor. In order to bring the various mechanisms, including the gear 7 reason, among others, the housing 28 reaches to one side of the axis of the screw a greater distance than to the fan side, as shown particularly in Figures 1 and 4.

It isnoted that since the feed screw and hopper are both driven from the same drive, they will operate together, so that when the screw is withdrawing fuel from the hopper, the hopper is also slowly rotating, and the sweep arms are carrying fresh fuel to the trough and feed screw. It will also be noted that since the tangent line [6 is well up from the horizontal (more than the angle of repose 'of such fuels) there will be no danger of the fuel hanging up in the hopper, but it will, at all times, move down easily and smoothly and without'the need of any agitator.

A suitable filler opening is provided in the upper portion of the hopper preferably centrally therein, and a suitable cover 29, hinged or otherwise, is provided for said opening. When this filler opening is centrally placed it will always occupy the vertical axial position, irrespective of the degree of rotation of the hopper at the time the filling operation is performed.

Manifestly, other suitable hopper forms may be used, generally symmetrical about a vertical axis, so that when rotated about such axis the fuel delivery to the trough will be symmetrical.

It is noted that due to the hopper rotation all portions of the hopper interior are brought into registry with the feed screw or other conveyor in succession so that all portions of the hopper will feed to the conveyor without the need of using agitators or other devices within the hopper itself. Also, that any given portion of the hopper (except its center), communicates alternately 9,199,770 with the front and back portions of the conveyor so that any tendency towards circulation of the fuel in the body of the hopper is eliminated.

This will, likewise, greatly reduce the segregation and degradation of the fuel, and will result in delivery of fuel to the conveyor in substantially the same condition as it was placed in the hopper.

I wish also to point out that containers of circular form may be designed with less material for a given cubical capacity than those with flat sides; and that a spherical container is the most economical of all circular types in this regard; and also that metal of lighter thickness or gauge may be used when the container is of circular form than when with flat sides.

While I have herein shown and described only certain embodiments of my present invention, still I do not intend to limit myself thereto except as I may do so in the claims.

I claim: 7

1. In a device of the class described, the combination with a fuel feed screw, and means for driving the same, of an open top trough in which said feed screw rotates, horizontal guide plates at the sides of said trough'constituting a floor, a spherical hopper centrally above the guide plates and trough and mounted for rotation about a substantially vertical axis intersecting the axis of rotation of the feed screw, the sphere of saidhopper having its lower portion cut away on a plane substantially coincident with the guide plates, and said plane intersecting the spherical surface of the hopper substantially at the position of a tangent lying at fifty-five degrees to the horizontal, to thereby enable fuel contained within the hopper to naturally descend to the trough and guide plates, sweep arms on the hopper extending inwardly above the guide plates and moving with the hopper, there being a filler'opening in the upper central portion of the hopper,

. and common means for driving the feed screw I described.

and rotating the hopper simultaneously, substan- I tially as described.

2. In a device of the class described, the combination with a fuel feed screw, and means for driving the same, of an open top trough inwhich said feed screw rotates, horizontal guide plates at the sides of said trough, constituting a floor, a

spherical hopper centrally above the guide plates and trough and mounted for rotation about a substantially vertical axis, the sphere of said hopper having its lower portion cut away on a plane substantially coincident with the guide plates, said plane intersecting the surface of the sphere at a position such that the tangent to the sphere at such point of intersection is substantially as steep as the angle of repose of material within the hopper, sweep arms on the hopper extending inwardly above the guide plates and moving with the hopper, there being a filler opening in the upper central portion 01' the hopper,

and common means for driving the feed screw and rotating the hopper simultaneously, substanplates, sweep arms 'on the hopper extending inwardly abovethe guide plates and moving with the hopper, there being a filler opening in the upper central portion of the hopper, and common means for driving the feed screw and rotating the hopper simultaneously, substantially as RAYMOND n'. YOUNG. 

